Help with regex

Ruby
1

i have this string
a=“USD.CHF.ABC”
irb(main):024:0> a.match(/^USD/)
=> #MatchData:0x2e6be30
irb(main):025:0> $1
=> nil

i want to use regex to see if it matches USD as first 3 characters and
here is my attmept. I am not sure why there is no match, any help is
appreciated.

2

On Nov 21, 5:46 pm, Junkone [email protected] wrote:

i have this string
a=“USD.CHF.ABC”
irb(main):024:0> a.match(/^USD/)
=> #MatchData:0x2e6be30
irb(main):025:0> $1
=> nil

i want to use regex to see if it matches USD as first 3 characters and
here is my attmept. I am not sure why there is no match, any help is
appreciated.

You can either assign the MatchData that match returns to a variable:

m = a.match /^USD/
m[0]

or you can use parens in your regex to capture the match into $1:

3

Junkone [email protected] writes:

appreciated.
Actually, there was a match and a MatchData object was returned (which
you silently ignored).

Maybe this example will help:
IRB-> match_data = “USD.CHF.ABC”.match(/^USD/)
=> #MatchData:0x578744
IRB-> match_data.to_a
=> [“USD”]
IRB-> match_data = “CHF.ABC.USD”.match(/^USD/)
=> nil

Hope that helps.

4

From: Junkone [mailto:[email protected]]

a=“USD.CHF.ABC”

irb(main):024:0> a.match(/^USD/)

=> #MatchData:0x2e6be30

irb(main):025:0> $1

=> nil

$1 want captures, try

a
#=> “USD.CHF.ABC”
a =~ /^USD/
#=> 0
$1
#=> nil
$&
#=> “USD”
$~[0]
#=> “USD”

kind regards -botp